TWO days after she gave birth to her daughter, Liana Gedz couldn’t understand the pain.

Her stomach hurt in the wrong place, she kept thinking, in a spot suspiciously high on her abdomen. After two years and two devastating miscarriages, Liana’s beloved daughter, Emma, had been delivered by emergency Caesarean section at Beth Israel Medical Center, six weeks premature.

But even after all she’d endured, this pain was too fierce, too strange. Other things, too, seemed not quite right.

Why, Liana wondered, was everyone at Beth Israel — nurses, residents, aides — so eager to take a peek under her bandages?

On Sept. 9, 1999, Liana Gedz learned the truth. And it would change not only her life, but the lives of every woman in this city who ever trusted her body to a man with a scalpel.

Into her hospital room walked her obstetrician and dear friend, Dr. Allan Zarkin. He was with Beth Israel’s chairman of obstetrics, Dr. Daniel Saltzman.

“I know what happened in the operating room,” Saltzman told her ominously, she said. “I came to see that.”

“See what?” Liana demanded. “See what?”

A growing fear temporarily dislodged her pain, and Liana turned to her husband, Bob Ghalili.

“Give me a mirror!” she insisted over and over until, reluctantly, he complied.

Lifting the small mirror to her stomach, Liana saw what was causing her agony. There, carved deep into her abdomen, puffy, red and swollen in Liana’s torn, infected flesh, were the unmistakable letters — “AZ.”

AZ. Allan Zarkin.

“Allan — why would you do it to me?” Liana shrieked.

And suddenly, the kindly doctor’s features darkened, revealing a stranger. He issued an unforgettable reply.

“After the way I took care of you, I don’t have to give you any f—-ing explanation,” Zarkin told his patient.

Then he turned on his heel and walked out of the room.

THE case of Allan Zarkin, 61, now known far and wide as “Dr. Zorro,” is one of the more bizarre malpractice cases to hit this city. It involves a doctor who claims to suffer from a serious brain disorder, and the unsuspecting patients who were treated by this walking medical time bomb.

But it is also a chilling tale of how one of this city’s largest and most respected hospitals, Beth Israel, protected a demented doctor — allowing Zarkin to continue practicing medicine months after he maimed Liana Gedz.

At its heart, though, it is a story of trust and betrayal. Of a couple who saw their dreams of a child fulfilled by Dr. Zarkin — only to have their joy twisted into an incomprehensible nightmare.

“You’ve got to understand, he was like a father to me,” Liana said, tears streaming from her pale-blue eyes.

“He was like a god to me,” and she cried harder.

“If only he had said he was sorry, I probably would forgive him,” she whispered. “He gave me the child he promised.”

Zarkin never apologized. Instead, he and Beth Israel settled a lawsuit last Friday with Liana Gedz, said her lawyer, Robert Sullivan, for a reported $1.75 million. Her case is over.

But how can you forget, when a man’s initials are carved into your body?

I met with Liana and Bob at their Manhattan apartment Thursday night for an exclusive interview. Between bites of takeout Malaysian food and puffs from Liana’s slim Capri cigarettes — “For my nerves,” she explained sweetly — their story came tumbling out.

Liana Gedz, a Russian-born dentist, is a striking woman — tall with long, blond hair and a shy smile. As Baby Emma, now 5 months old, slept in her nursery, I awkwardly asked Liana to show me the scar. She led me into a bedroom and lowered her sweatpants.

The letters on her abdomen — 3-inches wide and an inch high — are still red and puffy in places. Zarkin, she explained, cut deep and did not suture the wound, which continually reopened, leading to infection.

“It doesn’t look so bad,” I manage to stammer. But Liana cast a gentle glance that said we both know that’s a lie.

“Every time I take my clothes off, I see it,” Liana said.

“Every time my husband looks at me, he can see another man’s initials on my stomach.”

LIANA, 31, and her 34-year-old husband, an oral surgeon, met four years ago at a dental conference.

“From the first date, I knew I was going to marry this guy,” Liana said. They are the kind of couple who complete each other’s sentences. They have much in common.

Robert Ghalili, an Iranian Jew, fled his native country in 1979 with his brother when they were 11 and 13, on what he describes as the “last plane out of Persia.” From Germany, the boys made it to America as political refugees. Their parents later joined them.

Liana, a Russian Jew, came to the United States with her family 10 years ago, also as a political refugee.

A year after they met, they married. Liana became pregnant within 10 days of the wedding.

It wasn’t meant to be.

In May 1998, after eight months of pregnancy, Liana delivered a full-term baby girl at NYU’s Tisch Hospital. The newborn was dead. As Liana cradled her lifeless baby in her arms, she realized it was the first time she’d ever held an infant.

Liana sank into deep depression. Shortly after the miscarriage, a friend offered a solution that, at the time, Liana and Bob believed was the answer to their prayers. The friend introduced them to Dr. Allan Zarkin.

“Dr. Zarkin said to me, ‘I guarantee you a baby,'” said Liana.

After taking the fertility pill Clomid, Liana soon became pregnant again. She miscarried after eight weeks. This time, it was Dr. Zarkin who kept her from sinking into blackness.

“He was always there for me. He used to call me on the phone. He really wanted me to get pregnant,” she said.

Gedz, her husband and Zarkin would meet for dinner at a restaurant or at the couple’s apartment two or three times a week. Zarkin had an effusive, boisterous manner and wore colorful clothes. In hindsight, Bob admits he was taken aback at times by Zarkin’s boasts about his sexual exploits. Liana, too, harbored reservations.

“He used to talk about patients. He once called me and said [about a woman’s pubic hair], ‘I could braid that hair.'”

Zarkin’s seeming dedication caused them to overlook the comments. Besides, a month after the miscarriage, without the benefit of fertility drugs, Liana was pregnant again.

After 24 weeks, she went into premature labor. She was admitted into Beth Israel, she said, and for the next 2 ½ months, remained there on bed rest. On Sept. 7, 1999, six weeks before Liana’s due date, the baby went into distress and Zarkin performed an emergency C-section.

The operating room was crowded. In addition to the doctor and patient, Bob, Liana’s mother, a resident, two nurses, an anesthesiologist and an assistant were in attendance.

So how did Zarkin get away with it?

Bob takes the pen from my hand, and enters six even strokes into my note pad. The strokes form the initials AZ. It took less than two seconds for Bob to make the mark.

“That’s how fast it was,” said Bob. He said he watched Zarkin wield the scalpel, but did not realize what he’d done until afterward, when Zarkin dabbed at his wife’s abdomen with gauze.

But Bob decided not to tell his wife immediately. She had waited so long for this baby, and suffered so much.

Emma came into the world bluish in color, weighing just 4 pounds, 11 ounces. Bob knew his helpless wife and newborn baby were at the complete mercy of Beth Israel Medical Center and Dr. Zarkin.

At this point, his most fervent goal was to get his family home alive.

IF THE carving was a hideous violation, some consider the apparent attempts to cover up the deed even more heinous.

“This couple has to be compensated for their tremendous pain and suffering, but the other thing we’re trying to accomplish is to bring about public access into the secret world of the medical profession,” said Sullivan, their lawyer.

Beth Israel suspended Zarkin on Sept. 9 — two days after Emma was born. It wasn’t soon enough.

After the child was born, Zarkin, according to a confidential state report, followed her to the neonatal intensive-care unit, where he tried to remove a breathing tube from her face, until “physically restrained” by a nurse.

Yet Beth Israel did not report any of these details — from the carving to his potentially dangerous behavior toward the baby — to the state, choosing only to say the doctor committed “gross misconduct.” And so Zarkin kept his medical license until early this month.

There’s more. Liana and Bob claim Zarkin and the obstetrical chief, Dr. Saltzman, each asked the couple to sign documents that would absolve Zarkin of blame for the carving. They refused. Beth Israel spokesman Jim Mandler said he had no knowledge of such a request.

However, after I reported the extent of Saltzman’s efforts to protect Zarkin, Saltzman abruptly stepped down as chairman of obstetrics. He remains on staff.

The state Health Department fined Beth Israel $14,000 and ordered the facility to clean up its act.

Zarkin, for his part, has claimed he suffers from an Alzheimer’s-like brain disorder called Pick’s disease. His lawyer, Kenneth Platzer, has ignored repeated calls for comment.

IT MAY come as a surprise that Liana and Bob do not want to see Zarkin — indicted last week by a Manhattan grand jury — prosecuted as a criminal.

“He’s not a danger to society without his scalpel,” Liana said. “If they want to help him, put him in a psychiatric ward.”

Does she feel sorry for him? Not entirely. But she is anxious to get on with her life.

This is going to be rough. Liana hasn’t worked since Emma was born. And the couple, who once planned to have more than one child, are terrified of again putting themselves at the mercy of the medical establishment.

And then, there’s the scar. To erase the mark of Zarkin, Liana faces extensive plastic surgery. Not to mention paralyzing fear.

“I trusted Dr. Zarkin,” Liana said. “Now, how do I know, when I’m under anesthesia, that another doctor won’t do something terrible?”